91391835397 has 2 divisors, whose sum is σ = 91391835398. Its totient is φ = 91391835396.

The previous prime is 91391835373. The next prime is 91391835401. The reversal of 91391835397 is 79353819319.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81915591681 + 9476243716 = 286209^2 + 97346^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91391835397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91391835097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45695917698 + 45695917699.

It is an arithmetic number, because the mean of its divisors is an integer number (45695917699).

Almost surely, 2^91391835397 is an apocalyptic number.

It is an amenable number.

91391835397 is a deficient number, since it is larger than the sum of its proper divisors (1).

91391835397 is an equidigital number, since it uses as much as digits as its factorization.

91391835397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5511240, while the sum is 58.

The spelling of 91391835397 in words is "ninety-one billion, three hundred ninety-one million, eight hundred thirty-five thousand, three hundred ninety-seven".